Adjustable wrist pin



W. A. HOBLIT ABLE WR l sT P N. FEB. 24, 1921 ADJUST F1 LED Jan. 30, 1923.

Jan. 350, i923.

VTS

WILLIAL A. HOBLIT, GF LOS ANGELES, CALFORNIA.

ADJUSTABLE WRIST PIQ'.

Application ed February 24'-, 192i.

1 o @ZZ idiom. 'it may conce/m:

.Be it lin-own that l, lil/Tinnriiir A. Henna, a citizen oil the United States, residing at Los ngeles. county of Los Angeles, and State ot California. have invented a new and useful Improvement lComprisingr an i-idjustable Vrist lin, of which the tollowing is a speci'iication.

illy invention relates to pins used to pro vide bearings in machinery and particularly to wr' t pins such as are used in inter-nai comi, :.nvcn engines for the purpose ot pro` viding a pivot in the piston t'or the attachnient ot a connecting rod.

The principal object of the invention. is to provide a pin which may be expanded to compensate 'tor wear.

il. further object ot the invention is to provide a wrist pin which has a certain amount ot' elasticity to prevent seizing due to the diiierence in expansion and contraction ol the parts under variable temperaturerifl and in the event that the lubrication is 'faulty'.

Further objects and advantages will be made evident hereinafter.

Referringto the drawingi which is 'for illustrative purposes only,

Fig. l is a cross section through an ternal combustion engine eeuipped with invention.

Fig. 2 is a central longitudinali section through one embodiment of my invention, and,

Fig. 3 is a section on a plane represented by the line 3-3 ot Fig. 2.

i Fig. Llis an elevation ot' an alternate torni ot my invention.

Fig. 5 is an elevation of another alternate torxn ot my invention.

Fig. G is an elevation partly in section ot still another alternate t'orm ot my invention.

In the standard orm of internal combustion engine, a piston 1l is provided sliding in a cylinder casting l2. A connecting rod i3 extends up inside the piston and engages a wrist pin le.

'lhe embodiment oi my in ,'ention to be described relates to the specific construct-ion ot' this wrist pin in combination with the other parts ot the engine.

ln the embodiment of my invention shown in Figs. 2 and 3, 2O is a hollow cylindrical sleeve forming the wrist pin 1d and having` tapered threads 2l in either end thereot. Screwed into the tapered threads are plugs QQ, the taper on the threaded ei:-

Serial No. 447,372.

terior the plug being slightly greater than the taper on the interior oi. the member 20. The sleeve 20 is provided with a slot 25 which extends entirely through into the central cavity therein throughout its length. ll`he sleeve 20 is used in the place cit the standard wrist pin and may be ai'- ranged so that it is fixed in the connecting rod andA oscillates therewith or so that it iixed in the piston thus providing' a central bearing tor the connecting rod. ln some forms of my invention the wrist pin is 'l'irce to turn in both the piston and the connecting rod. rif he methods of fastening,` the wrist pin in the piston or in the count-acting` rod are not shown as they are standard in the art and various in their nature. The construction of the plugs'ZQ is such that the threads thereof engage firmly only near their outer ends, there being a slight clearance with the walls ot the sleeve 2O at itsl inner ends due to the greatertaper ot the plugs Q2. Slots 27 are provided in the plugs 22 so that they can be screwed in and out.

ln practice the sleeve 2O is made out proper size to give a goed working fit in the piston il and the connecting rod 13. After the engine has been run Yfor a considerable period, the parts wear so that too much clearance exists around the w ist pin le and a slight knock may be detected by one skilled in the art. t is then possible bytorcingl the plugs 22 inwardly to expand the sleeve 20, increasing its eiective diameter and tal;- ing up the clearance.

ln practice l prefer to out a full V thread on the exterior ot the plugs 22 making a i/ thread of only about one third the depth of the thread ou the plug 22 in the inner surface ot the sleeve 20. lThis prevents the sleeve from being as much weakened by the threads as it would .be were a full thread cut.

lt should be noted that due to the torni of the sleeve 20, and the plugs 22, considerable elasticity exists both in the center oi the sleeve and at its ends. That is both the extremel ends and the center may, be swung; inwardly, the plugs 22 forming a rigid ulcrum between each and the center oiI the sleeve. Since this elasticity exists, the sleeve 2O is much less likely to seize in the event or" changes in diameter ot the sleeve or the holes in which it lits due to expansion or contraction. or in the event ot insuiiicient lubrication.

Figs. 4i and 5 show modifications '-1 which the slots do not run in a straight line but are curved as shown in those figures.

ln Fig. 6 is shown s sleeve which is not out entirely through. one slot 30 being eut in one Side for about two thirds the length ot the pin. a similar slot 3l being` diametrically ophosite the slot 30 and extending trom the opposite end.

l claim as my invention:

pin for providing :i bearing' surface in nmehines Comprising: e hollow sleeve having :i cut in one side thereof and trustro conical members threaded inside said sleeve for expanding said sleeve, the taper on seid members being greater than the taper of the opening in which seid members are secured.

In testimony whereof, I have hereunto set my hand et Los Angeles, California, this 17th day ot' February, 1921.

WlLLL-ili A. HOBLT. 

